Circuit interrupter construction



Dec. 17, 1957 s. 1. LINDELL CIRCUIT INTERRUPTER CONSTRQCTION 3Sheets-Sheet 1 Filed March 6, l956 INVENTOR. figgardZZL/Zdfl, BY

Dec. 17, 1957 s, DEL 2,816,981

CIRCUIT INTERRUPTER CONSTRUCTION IN VEN TOR.

Dem 771- s. 1. LINDELL 2,816,981

cmcun INTERRUPTER CONSTRUCTION Filed March e. 1956 3 Sheets-Sheet 374492335 flj/ 60 United States Patent CIRCUIT INTERRUPTER CONSTRUCTIONSigurd I. Lindell, Chicago, 11]., assignor to S & C Electric Company,Chicago, Ill., a corporation of Delaware Application March 6, 1956,Serial No. 569,909

20 Claims. (Cl. 200-114) This invention relates, generally, to circuitinterrupters and it has particular relation to such devices foroperation in conjunction with disconnecting fuses, disconnectingswitches and the like for opening them under load without drawing anexternal arc. This invention is an improvement over the inventions ofLindell Patent Nos. 2,671,142 and 2,671,145, both issued March 2, 1954,and Lindell application Serial Nos. 412,182, filed February 24, 1954,and 493,083, filed March 9, 1955.

Among the objects of this invention are: To provide an improved circuitinterrupter for opening under load disconnecting fuses, disconnectingswitches and the like without the formation of an unconfined arc; toprovide for random location of one of the separable contacts of theinterrupter with respect to its cooperating contact; to mount the oneseparable contact and the associated trailer, spring and cable assemblyand conducting rod for free rotation about the longitudinal axis of theinterrupter; to protect the inner surface of the inner insulating sleevefrom the heat of the are that is drawn when the contacts separate underload; to facilitate the escape of the products of the arc by increasingthe nun1- ber of escape passageways and placing them close to the arc;to limit the extent that the inner sleeve can be withdrawn from theouter tubular insulating housing; to employ an insulating key forguiding the sleeve in its move ment through the housing; to secure ametallic sleeve end insert to one end of the sleeve and a sleeveterminal to the other end of the sleeve by interfitting tapered jointsheld together by cement; to counterbalance the circuit interrupter whenthe inner sleeve is withdrawn to the maximum permissible extent from theinsulating housing; to enclose the counterbalancing mechanism within theconducting arm which extends from and is movable with the inner sleeve;to employ a spring pressed plunger cooperating with a cam on a strutpivot shaft to provide the counterbalancing action and to limit themovement of the plunger; and to bias the keeper by means of a springpressed plunger completely enclosed in the strut for returning it to acentral position with respect to prong adapted to engage a currentcarrying member of the device that is to be opened under load withoutexternal arcing.

Other objects of this invention will, in part, be obvious and in partappear hereinafter.

This invention is disclosed in the embodiment thereof shown in theaccompanying draWins and it comprises the features of construction,combination of elements and arrangement of parts that will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of thisinvention reference can be had to the following detailed description,taken together with the accompanying drawings, in which:

Figure 1- is a perspective view of a circuit isolating 2,816,981Patented Dec. 1?, 1957 device such as a disconnecting fuse, showing howthe auxiliary circuit interrupter of the present invention can beapplied thereto, the particular circuit isolating device being thatdisclosed in Lindell application Serial No. 435,747, filed June 10,1954, now Patent No. 2,745,921 issued May 15, 1956, and assigned to theassignee of this application;

Figure 2A is a vertical sectional view, at an enlarged scale, of theupper portion of the auxiliary circuit interrupter shown in Figure 1;

Figure 2B is a vertical sectional view, at an enlarged scale, of thelower portion of the auxiliary circuit interrupter shown in Figure 1,the arrangement being such that when Figure 2B is placed below Figure 2Aand in alignment therewith a longitudinal cross-sectional view of thecomplete auxiliary circuit interrupter is provided;

Figure 3 is a horizontal sectional view taken generally along the line33 of Figure 2B;

Figure 4 is a view, in side elevation, of the inner contact sleeve;

Figure 5 is a vertical sectional view taken generally along the line 5-5of Figure 2B; and

Figure 6 is a vertical sectional view taken generally along the line 66of Figure 2A.

Referring now particularly to Figure 1 of the drawings, it will beobserved that the reference character 10 designates, generally, acircuit isolating device of the disconnecting fuse type. As pointed outhereinbefore, the de tails of construction of the circuit isolatingdevice 10 are set forth in Lindell application Serial No. 435,747, filedJune 10, 1954. Accordingly, only a general description of this devicewill be set forth here. While particular reference is made to adisconnecting fuse device, it will be understood that the presentinvention can be employed where the fuse tube of the disconnecting fuseis replaced by a metallic conducting tube or it can be used inconjunction with a disconnecting switch that is modified suitably foruse in conjunction with the auxiliary circuit interrupter mounted on alive line stick as described hereinafter.

The circuit isolating device or disconnecting fuse 10 includes aninsulator 11 which is arranged to be stationarily mounted on a cross armor the like and has a lower terminal contact member 12 carrying aconnector 13 for connection to a line terminal. Pivoted at 14 on thelower contact member 12 is a lower current carrying member 15 that ispositioned at the lower end of a fuse tube 16. At its upper end the fusetube 16 has an upper current carrying member 17 which is positioned incontact engagement with a normally energized con tact member 18 carriedby the upper end of the insulator 11. In order to remove the uppercurrent carrying member 17 from contact engagement with the terminalcontact member 18, the former is provided with an eye or pull ring 19 ofconducting material for receiving the prong of a live line tool. Inaccordance with conventional practice, the fuse tube 16 is manipulatedby inserting the prong of the live line tool in the eye or pull ring 19for swinging the upper current carrying member 17 into or out of contactengagement with the terminal contact member 13.

For urposes more fully disclosed in Lindell application Serial No.435,747, filed June 10, 1954, the terminal contact member 18 includes anL-shaped reinforcing bar 20 having a downwardly extending arm 21 whichcarries a guide 22. The guide 22 is employed, in part, for guiding theupper current carrying member into proper contact engagement with theterminal contact member 18. The guide 22 includes forwardly extendingarms 23 at the outer ends of which are transversely extending horns orstuds 24. Provision is made for connecting the energized line con ductorto the terminal contact member 18 through a terminal pad 25. It will beunderstood that the upper portion of the terminal pad (not shown)carries a connector or like device to facilitate connection of theenergized line conductor thereto.

It is often necessary to open the circuit isolating device ordisconnecting fuse 10 while it is carrying loadcurrent. When suchoperation is performed, an arc is drawn between the upper currentcarrying member 17 and the terminal contact member 18 which is likely todamage the parts which are contacted by the arc and also, where othercircuits are involved, is likely to fault one or more circuits in theevent that the arc is drawn and should jump to another circuit or theground. Also there is the likelihood of injury to the operator.invention, provision is made for safely and expeditiously opening thecircuitisolating device llll while it is carrying line current. It isfor this purpose that an auxiliary circuit interrupter, shown generallyat. 27, is employed.

It will be observed that the auxiliary circuit interrupter 27 isprovided near its upper end with an eye' member or pull ring that isshown generally at 28-. The eye member or pull ring 28 includes a bowshaped contact member 29, Figure 2A, which had oppositely extendingtrunnions' 30 that arerockably mounted by parallel end portions 31 of apair of arms 32 that are formed integrally with and extend radially froma pull ring 33. It will be understood that the bow shaped contact member29, as shown in Figure 1, is positioned over one of the horns or studs24 for connection to the normally energized terminal contact member 18-of the circuit isolating device 10. In addition, this connection: isboth an electrical and a mechanical connection and serves as an anchorfor resisting an endwise' pull applied to the auxiliary circuitinterrupter 27, in a manner to be described, not only for operating thefuse tube 16 tothe open position but also for subsequently operatingthe'auxiliary circuit interrupter 27 to interrupt the flow of load currenttherethroug'hwithout causing an unconfined arc.

Connection to. the upper current carrying member 17 is provided bycontact means 34 in the form of a pin or prong that is carried by asupport member 35 in the form of a strut, preferably formed of aluminum,on which the auxiliary circuit interrupter 27 is flexibly mounted by auniversal joint that is indicated, generally, at 36 in Figures 1 and 2Bof the drawings. The support member or strut 35 has an. integralextension 37 provided with a claw bracket 38 that can be secured-by aclamp screw 39 to a similar claw bracket 40 which is formed integrallywith a fitting 41 that is arranged to be carried by one end of a liveline stick a ortion which is shown at 42 in Figure 1-.

In orderv to insure that the pin or prong 34- remains in engagement withthe eye or pull ring 19, which constitutes an integral extension of theupper currentcarrying member 17, a rotary keeper 43 is employed which,as will appear hereinafter, is mounted to swing about two axes that areright angles to each other in order to permit entry of the pin or prong34 into the eye or pull ring 19 and for holding the same in operativeposition therein.

Referring now to the upper portion of Figure 2A of the drawings, it willbe observed that the pull ring 33 is keyed at 46- to a pull ring bushing47 which is cemented onto the upper end of a tubular insulating housing48 that is formed of a phenolic condensation product or the like whichis capable of providing the desired insulating qualities and ismechanically strong. The pull ring 33' telescopes over the bushing 47and is held in position thereon, in part by the key 46 and in part by acrescent snap ring 49. It will be understood that the pull ring 33 andbushing 4'7 form a part of a stationary contact assembly at the upperend of the tubular insulating housing 48' and-such assembly isdesignated, generally, by the reference character 50. The arrangementand construction of the pull ring 33 and bushing 47 whereby the latteris removably mounted on the In accordance with the present 4 former aredisclosed and claimed in application Serial No. 571,472, filed March 14,1956.

Included with the stationary contact assembly 50 is an end cap 51 thatis threaded into the upper end of the pull ring bushing 47. The end cap51 is provided centrally with a depending hollow boss 52 having anupwardly facing annular shoulder 53 for cooperating with a shoulderedretaining nut 54 for receiving the threaded upper end 55 of a rigidconductor rod 56. A lock nut 57, threaded on the upper end 55, has snugfitting engagement with the lower end of the retaining nut 54 with thelatter projecting slightly below the lower surface of the boss 52 sothat a clearance 58. is providedv between it and the upper surface ofthe lock nut 57. A set screw 59 secures the conductor rod 56 in positionin the retaining nut 54. This construction permits the rigid conductorrod 56 to rotate about its longitudinal axis with respect to the end cap51 and thus permits the random positioning of an arcing contact (to bedescribed hereinafter) carried by the conductor rod 56 with respect to acooperating arcing contact.

At the lower end of the conductor rod 56 is a cam ter' minal 61 which isprovided with a conically shaped shoulder 62 and an upwardly facingannular stop shoulder 63. The purposes of these shoulders will bedescribed present 1y.

Referring now to Figure 2B of the drawings, it will be observed that thelower portion of the cam terminal 61 has a spring and cable assemblyconnected thereto. comprising a coil tension spring 64 and a flexibleconductor or cable 65. At their lower ends they are connected to theupper end of a movable first arcing contact 68 which is generallycylindrical in cross section and to which a trailer 69 of gas evolvingmaterial is connected by a trailer stud 70. The construction of thetrailer 69 and stud 70 is described in more detail in Mikos applicationSerial No. 545,044, filed November 4, 1955, and assigned to the assigneeof this application.

Threaded onto and movable with the first arcing contact 68 isa tubularmetallic sleeve 71 which extends upwardly through the tubular insulatinghousing 48 to a position below the contact assembly 50. A stop ring 72'is carried by the upper end of the metallic sleeve 71, as shown inFigure 2A of the drawings, and extends around its inner surface. Thestop ring 72 is provided for engaging the stop shoulder 63 on the camterminal 61 under certain conditions. If the first arcing contact 68should be prevented by friction or otherwise from disengaging itscooperating contact 110 despite the tension applied by the spring 64,then continued downward movement of the inner sleeve 77 after engagementof the stop shoulder 63- by the stop ring 72 and arresting of furthermovement of the first arcing contact 68 will break loose the secondarcing contact 110' and permit the spring 64 to function in its intendedmanner. In the event that the spring 64 should fail for some reason, thecontacts 68 and 110 will be separated a substantial distance, forexample, about half the break distance that results when the spring 64is able to function normally.

With a view to moving the tubular metallic sleeve 71 downwardly forstressing the spring 64 a trigger or latch 73 is pivotally mounted at 74on a trigger frame 75 which is secured to a metallic inner sleeve endinsert 76 that is carried by the upper end of an inner insulating sleeve77 that is formed of a material, such as phenolic condensation product,that is capable of providing thedesired insulation and in addition hassuitable mechanical properties.

It will be observed that the metallic inner sleeve end insert 76 has aportion 78 that telescopes with the upper end portions 79 of the sleeve77 and that these portions are. tapered. A layer 80 of suitable cementbetween theoverlapping portions 78 and.79 serves-to hold the insert.

76 firmly in place on the inner insulating sleeve 77 and provides amaximum of. strength with a minimum of combined cross section. Further,this arrangement provides the maximum attainable cross section at eachend of the sleeve 77 with substantially the same inside and outsidediameter at the ends of each point.

It will be understood that, when the inner insulating sleeve 77 is moveddownwardly, it carries with it the trigger or latch 73 the lower end 81of which engages the upper end of the metallic sleeve 71 and thus causesit and the arcing contact 68 to move downwardly through the tubularinsulating housing 48 until the lower end 81 of the trigger or latch 73engages the shoulder 62 whereupon a slight further downward movementdisplaces the trigger 73 from engagement with the metallic sleeve 71 andpermits the same and the arcing contact 68, together with the trailer69, to move upwardly under the influence of the spring 64 forinterrupting the circuit in a manner to be described in more detailhereinafter.

It is desirable that the inner insulating sleeve 77 be freely movablelongitudinally in the tubular insulating housing 48 but that it beprevented from rotating about its longitudinal axis with respectthereto. Accordingly, a slot 83 is provided in the outer surface of theinner insulating sleeve 77 longitudinally thereof for receiving a tongueor pin 84 that is formed integrally with a ring 85 which is cemented, asshown in Figure 2B, to the inner surface of the tubular insulatinghousing 48. Preferably the tongue or pin 84 and ring 85 are formed ofinsulation in order to reduce the likelihood of flashover of theauxiliary circuit interrupter 27 either externally or internally afterthe circuit has been opened therethrough.

The ring 85 serves as a stop to engage the under side of the triggerframe 75 and limit the outward movement of the inner sleeve 77. Theshock incident thereto is transmitted to the tapered cemented joints atthe ends of the sleeve 77.

In order to limit the upward movement of the metallic sleeve 71 afterthe trigger 73 has been tripped, a stop ring 86 is secured to themetallic sleeve 71 and is arranged to engage the underside of a stopring 87 that is formed preferably of insulating material and is cementedinto the sleeve end insert 76 at the upper end of the inner insulatingsleeve 77.

The arc which is drawn on movement of the arcing contact 68 upwardly isextinguished by the cooperation of the trailer 69 and the inner surfaceof a liner 88 that is formed of a material which evolves an arcextinguishing medium when subjected to the heat of an arc. Grooves 89and 90, Figures 2A and 2B, are provided in the liner 88 near its endsfor receiving 0 rings 91 and 92. The purpose of this construction is toprovide a gas tight seal between the outer surface of the liner 88 andthe inner surface of the insulating sleeve 77 that is coextensivetherewith.

Cooperating with the arcing contact 68 is a movable contact assemblythat is indicated, generally, at 95 and located at the lower end of theinner insulating sleeve 77 in Figure 2B of the drawings. The movablecontact assembly 95 includes a contact sleeve terminal 96 which has aportion 97 that telescopes with the lower portion 98 of the insulatingsleeve 77. It will be observed that the portions 97 and 98, like theportions 78 and 79 at the upper end of the insulating sleeve 77, aretapered and that a layer 99 of cement is employed to secure the contactsleeve 96 to the lower end of the insulating sleeve 77. Thisconstruction, like the construction at the upper end, providessufiicient strength for resisting mechanical shocks to which theinsulating sleeve 77 and associated parts are subjected, particularlywhen the auxiliary circuit interrupter 27 is operated by impact movementof the live line stick 42 until the trigger frame 75 engages the ring 85to arrest such movement as described above.

The contact sleeve terminal 96 has a depending extennets of the are thatare drawn when the device operates.

Radial vents 102 are located around the periphery of the extension 100and communicate with the chamber 101 for placing the same incommunication with the atmosphere when the inner insulating sleeve 77 iswithdrawn from the tubular insulating housing 48. At its lower end theextension 100 has a hollow light transmitting plug 103 threaded therein.It is provided with radial vents 104 to permit discharge of the areproducts to the atmosphere. Within the hollow plug 103 is a screen 105that is cup-like and overlies the vents 102 and 104. It is provided forpreventing the discharge of solid particles through the vents.

Within the contact sleeve terminal 96 is an inner contact sleeve 106,Figure 4, which is provided with a radial opening 107 for receiving acontact locating screw 108 that is held in place by a set screw 109.Extending upwardly from and formed integrally with the inner contactsleeve 106 are flexible contact fingers 110 which, as shown in Figure 2Bof the drawings, are arranged to engage the outer surface of the firstarcing contact. It will be understood that the flexible contact fingers110 constitute a second arcing contact and that it is between thesearcing contacts that the arc is drawn on operation of the auxiliarycircuit interrupter 27. A generally cylindrical contact spring 111cooperates with the contact fingers 110 to urge them into contactengagement with the outer surface of the first arcing contact 68.

With a view to facilitating the escape of the gas generated onseparation of the arcing contacts 68 and 110, longitudinally extendingslots 112 are provided between the contact fingers 110 as shown inFigures 2B, 3 and 4 of the drawings. The flow of gas incident to theseparation of the arcing contacts then can take place outwardly throughthese slots 112 and through radial vents 113 which are located in thecontact sleeve terminal 96. It will be observed that the vents 113 arecoextensive with the lower ends of the slots 112 and that they areuncovered when the insulating sleeve 77 is withdrawn from the tubularinsulating housing 48. Also, some of the gas flows over the upper endsof the contact fingers 110 and downwardly through the annular spacebetween them, the sleeve 77 and the contact sleeve terminal 96 to thevents 113.

A substantial amount of heat is generated when the are is drawn betweenthe arcing contacts 68 and 110. In order to prevent damage to thesurrounding inner surface of the inner insulating sleeve 77 an arcshield 114 is secured to the latter by cement. As shown the arc shield114, which is formed preferably of an arc resisting material such asstainless steel or a refractory material, is coextensive with the lowerend of the liner 88 and the upper ends of the flexible contact fingers110.

Near its lower end the tubular insulating housing 48 is provided with alongitudinally extending slot 115 through which a conducting arm 116projects and extends along the housing 48 toward its upper end. It willbe observed that the contact locating screw 108 and set screw 109 arelocated in the lower end of the conducting arm 116.

The universal joint 36, previously referred to, is located at the upperend of the conducting arm 116. For this purpose there is provided asocket 117 the axis of which is along the longitudinal axis of theconducting arm 116. Bearings 118 and 119 are formed integrally with thearm 116 on opposite sides of the socket 117 with the axis thereof atright angles to the longitudinal axis of the socket. Slidably mounted inthe socket 117 is a spring plunger 120 having a flat head 121 theperiphery of which has a sliding fit in and is guided by the counterbored upper portion of the socket 117. The lower end of the springplunger 120 extends into a reduced diameter bore 122 at the base of thesocket 117 and is guided thereby for movement along its longitudinalaxis under the influence of a coil compression spring 123 which, as

shoWnin FigureZB, reacts' between thebase ofithe socket 117a'ndtheunder'sideofthe fiat 'headllZl. The downward movement of thesprin'g"'plunger"120 is limited by 'theengagement of the un'dertsideof'the fiat head 121 with 'a"slronlder 124. 'The arrangementtis' such'thatthis engagement takesplace before the "spring 123 is fully compressed.This avoids likelihood of 'injury 'to Tithe spring" whichrnight occur ifit were" permitted to go's'olid. It willbe understood'that'the spring123"is .siifiiciently powerful so "that, in cooperation w'ithitheuniversal. joint 36,"'itis capable"'of'counterbalancingftheweight of theauxiliarypireuit'interrupter"27 not onlywherr itis in "the collapsedposition as shown in Figures 1,"2'A an'd2B'of thedra'Wings, but alsowhenthe inner insulating sleeve 77 and parts associated therewith'arewithdrawn from the tubular insulating housing "48" to'"the' full extentrequired' for 'fie'ctin'g circuit interruption.

lou'rnaled' inthe' bearings 1'18 and 119 is a "strut pivot shaft12'5""that' is formed "of'a'n'inner endyportion 126 and'an'outer'endportion12 7. 'These'portio'ns are interconnected by a set screw'I28'that.is held in position by a locking set"screw'129. 'As' shown'inFigure a 'rectangrlar cam 130 is positioned non-'rotatablybn'the strutpivot shaft IZS between the' portions .126' and 127.

Thus;'when the strut pivot shaft isrotate'd' in either direction;thereetangular cam cooperates with the flat'head 121' to depress thespring plunger"128'against the biasing action of the" spring 123. Thereaction is such that the's'pring 123'biases the'strut pi'votshaft 125to the centralpositi'onsho'wn 'inFigureS. This action is employed forcenteringthe supporfmernber or strut 35 in amanner to be describedpresently. The upper end of the'socket 117 above the strut pivot'shaft125 is close'd 'by apivotcover 131.

Itwill be'observed inFigure 2B of the drawings that the-outerend'portion '127 of the strut pivot shaft'125 projects outwardlybeyondthe "bearings '119. It is arranged torece'ive a pivotpin134 on'which theextension 37 of 'thesupport member or strut'35 is rockably mounted. Aspring 135 surrounds the pivot pin 134 and reacts between'oneside of thebearing 119' and the underside of the'extension'37 tobias the supportmember or strut35 in a direction toward the'tubular insulating. housing48. The movement of the support member or strut 35 under the influenceof the 'spring'1'35 is limited by a set screw 136which is threaded intothe extension 37 and bears against a wear resisting washer'1'36 formed,forexample, of stainless steel and overlying the bearing 119. A coverplate'137 is secured to the extension 37 by rivets and overlies theouter end of the opening in which the set screw'136 is located.

It is desirable to hoid the inner insulating sleeve77 in extendedposition after the separable contacts have opened the circuit in orderto prevent accidental reclosure of the circuit. For this purpose a latch138 is provided andis formed of suitable insulating material. At itslower end the latch 138 is rockably mounted on a pivot pin 139 whichextends transversely of the conducting arm 116 intermediate the ends ofthe socket 117 and belowthe strut pivot shaft 125. A spring 140 reactsbetween the latch 138 and the conducting arm116 to bias the formerinto'engagement' with the side of the tubular insulating housing '48.When the inner insulating sleeve 77 is withdrawn from the tubularhousing 48, the upper end 141 of the latch 138 is rocked by thespring140 into a posi- 7 tion underneath the lower end 142 of the tubularinsulating housing 48 and thus prevents the returnof the innerinsulating sleeve '77 until the latch 138 is moved out of lockingposition.

The'rnanner in which the rotary keeper-43 is rockably mounted" about twoaxes will now be described with reference to Figure 2A of the drawings.Near Tithe upper endbf the support 'm'e'm'beror strut.3'5' there isprovided a boss' 'l45' havinga' 'longitudinaltecess'.146 which extendsgenerallyparall'el tothe supportmember or strnt35 and at rig'htangles tothe pin or;prong .34. '..Bearings.147 and "I48.areiformed'integrallywith the .boss 145 at the upper'en'd of the longitudinal recess14'6.in..such position that their axis is at rightangles-totthe.longitudinalzaxis of the recess I46. At the'lowerend of.the recess-146 is a keeper plungerguide 149'tl1at is secured .inthe..position therein" by a'transverse pin 1 50. .Slidablymounte'd inthe opening in the guide 149.is astem 151 of.a keeper plunger I522whichis,provided witha. head 153 atits upper end. 'A coil compressionspring1154. surrounds the keeper plunger 152and reactslbetweent theunderside of the head'153 and the'keeper plunger guide .149 to bias the.keeper plunger. 1'52 upwardly. .-The downward movement of the keeperplunger'l'52iiszlimited by: the engagement of theshoulder .155 On.itsunderside with .the upper end 156 of the guideI149. '.The arrangementis suehthat this engagement takesplacebefore .thespring154 goes solidand thus injury thereto is prevented.

A keeper pivotfshaft-l'57.isjournaled in the bearings 147 and 148 and,as shownv more clearly in Figure 6 of .the drawings, 'it has a flat..cam surface 158 intermediate its ends whichoverliesthe .upperside ofthe head 153. It will be understood. that the. spring 154 acting throughthe keeper plunger.152.cooperateswith the-.fiat cam surface 158 tocenterlthe keeper. pivot shaft 157 regardless of the directionin-whichitis: rotated from the central .position.

At the outer. end of..the: keeper pivot shaft 157 there is a pivotpinlfilson. which the rotary keeper 4-3 ismounted. The keeper .43. isbiased-outwardly. to. the positionshown in Figure 2A of..the.-drawingsbyrneans-of a-coil compressionspring162 .thatis located in a bore 1'63of the keeperpivot .shaft..157t and. reactsagainst .a; plunger 164slidably mounted therein which bears against the inner side ofthe.keeper .43. .It willube understood that-the keeper 43 is.rotatablexabout thelongitudinal: axis of the keeper pivot..-shaft\157.and ina plane that-.is generally parallel to theplaneof.:the.support member. or strut 35. Also the-keeperi43is rotatableabout .the pivot pin 161 in a plane at right angles to. its plane ofrotation about the axis of the keeper pivot shaft 157. It can be .movedor rocked to the position. shown. by .the broken lines. Thus the keeperI43 can.be rocked inwardly relative to the pin orprong34 and alsoit can.be roekedsideways with respect thereto to facilitate. entryof the pinorprong 34 into the eye or pull ring 19, the'holding of .the pin or'prong34 within the. pull ring 19 and the removal thereof therefrom.

In orderto maintain contactengagernent with the eye or pull 'ring 19and. to -preventarcingbetween it and. the pin or prong'i34 acontactfinger, shown generally at 165, is provided. The contact finger165' includes a conducting sleeve 166 that is secured to one.end 167015a coil spring the intermediate portion 163 of Which-is positioned arounda shaft 169 that. extends transversely. of .the upper end of thesupportmemberor strut 35. The otherend 170 of the spring reacts againsta wall of the bearing 147 to the end that the contactifinger' 1 65 isbiased ina clockwise direction, .as viewed in 'Figure 2A, so that itsupper end moves in a. 'slofformed .between walls 171 to a positionagainst'the inside of. a depending flange 172 that is formed integrallywithtthe pin or prong 34.

in describing the operation of. the. auxiliarycircnit interrupter 27 itwill' be assumed thatthecircuit isolating device 10 is connected in a.line and is carrying current.

The lineman manipulates the livelinestick-tZ carrying the auxiliarycircuit interrnpter'ZTuntil.thebow shaped contact member'29 of the eyemember. or pull ring 28 overlies one of the horns or studs124. oftheguide. 22. It is assumed, of course, that the inner insulatingsleevc 77is positioned entirely within the tubular insulating housing 48 andthat. the circuitutherethrough-is.closed with the movable: first arcing.contact 68 inepgagernent with the contact fingers. 110. forming. thesecond-arcing contact. The circuit from the contact member 18 of thecircuit isolating device 10-now extends through the auxiliaryci'rcuitinterrupter 27 to the support member'or strut 35 and the ;pin;or-prong'34 carried thereby. Next the auxiliary circuit- =interrupter;27 is manipulated to position the pin-or prong 34 in the eye or pullring 19. When the pin or -prong -34 isrintroduced'into the eye or pullring 19,'--th'e k'eeper43'ismovedinwardly about the pivot pin161'and*is-rockedtogether with the keeper pivot shaft 157 as may-berequired to permit this action. Then the rotary keeper -43is centered bythe spring 154 to return to theposition-shown-in Figure 2A of thedrawings in alignment-with the pin'or prong 34. At the same timethecontact finger165*engages the eye orpull ring 19 and maintainscontact engagement therewith.

The lineman-now-exerts a downward -=pull on the live line stic'k 42.Since the pin or prong 34 is inserted in th'eeyeeor-pullring 19,andsincethe bow shaped contact mem-ber-"29 is held stationary by'the horn orstud 24, the inner insulating sleeve 77 is pulled out of thetubularinsulating housing 48. This is-accompanied by a movement oftheuppercurrent-"carrying member-17 out of engagementtwith the contact-member'18'. However, no

arc is formed th'erebetweensince these parts are shunted through-theauxiliary; circuit interrupter 27. The trigger or 'latch 73moves-downwardly withthe sleeve ,7 7 andafter-.;-a:slightwmovement-itslowerend 81 engages the ring '72 attheupper-end of the'metallic sleeve 71;

The-continued downward movement of thelive line stick -42 effectsafurtherswinging movement of the fuse tube-16-out-of the closed positionand afurther withdrawal of the inner insulating sleeve 77 from thetubular insulating housing 48. This is accompanied by an extension of'the flexible conductor. or-cable 65-and tensioning of the coilspring-64 as a result of the engagement by the lower-end 810i thetrigger 73 with the ring 72 at the upperendofthe tubular metallic sleeve71.

The-ends of: the spring64 are secured against rotation to the-lower-endof the cam terminal 61 and the upper end of th'e iirst-arcing contact68. As thespring 64 is tensioned on downward movement of the sleeve 77and 71a torsional-force is created that tends to close its coils andto'rotate the conductor -rod 56 as well as the arcing terminal 68 -withthe trailer-69; This torsional force is partly restrained byvthefrictional engagement of the lower end 81 of the trigger-orlatch 73 withthe ring 72 at oneendof thespring-64 and-of the retaining nut. 54

sleeve 7I 'together-with the arcing -contact68*upwardly-- through thehoreof the liner 88'together with the trailer 69.; An arc isdrawnbetween the contact 68-and the contact fingers 110 into the bore ofthe liner 88 and it is extinguished-byevolution of gas therefrom aswellas by gas from-the outer surface of the trailer 69 which'serves toconfine the are as is readily understood. By this time theinner-insulating sleeve 77 will have moved out of the lower endof thetubular insulating housing 48 sufficiently far to uncoverthevents104,192 and 113. The discharge of thegas generated bythe arc ispermitted through these.

vents. The vents 1.13 radially coextensive with the lower ends of theslots E12 between the contact fingers 110 serve to reduce rapidly thegas pressure and avoid undue application of pressure within the lowerend of the inner insulating sleeve 77 and-within the contact sleeveterminal 96.5

Another result of-the' release of the trigger or-latch73 'Qmrthe ringw72isrthe. release of the spring 64 touncoil.

. Whilethespring 64;is;.retrac,ting the firstarcing contact shapedcontact member 29 from the horn or stud 24,

68 and until the end of its stroke, the reaction is taken of the nut54'and good. contact engagement is maintained between it and the' boss52 of the end cap 51. The torsional force driving the return stroke setsup random rotation of the parts associated with the spring 64 and theyassume different positions, particularly at the end of the stroke. Thusthe first arcing contact 68 rotates with the trailer 69 and the arc isdrawn the next time at a different position with respect thereto and tothe liner 88 and the contact fingers 110. Since the metallic sleeve 71moves with the contact 68, the ring 72 is next engaged at a differentlocation by thelower end 81 of the trigger or latch 73. Thus the wearand erosion onthese parts are distributedjanditheirlives are prolonged.

A-fter theacircuitihas been. opened in the manner. described;thezcontinue'd downwardmovement of the live line tool 42icauses'thelatch 138' to engage the lower end 142' of the tubularz'insulatinghousing 48 with the result that the innerinsulating sleeve 77 is held inthe extended position. ASiPDiDtCd out, the spring 123 which forms a partof the universal joint 36 is of suflicient strength tocounterbalance-the.auxiliary circuit interrupter 27 in theextendedposition;

Thelineman now manipulates the live line tool 42 for thepurpose-ofdisengaging the pin or prong 34 from the eye :or; pull ring. 19;Then-the fuse tube 16 is permitted to; swingv downwardly to the openposition. Further manipulation of the live line stick 42'removes the bowIn this manner the'circuit isolating device 10 is opened without:thecreation ofvan .unconfinedarc and without requiring-thatthe: fuselinktherein be broken or blown. Subsequently. the fuse tube 16 can beswung tothe closed position torestore the circuit.

When the .bowshaped contact member 29 is removed from,contact'engagement with the horn or stud 24, it is deenergized: Then.the latch 138 can be moved manually from-registry with the lower end1420f thetubularinsulating housing 48 and the auxiliarycircuitinterrupter .27 carrbe reclosed. by manually returning the innerinsulating sleeve 77 to the position. shown in.Figures 2A and 2B ofthedrawings.

Since certain further changes can bemade in the foregoing constructionand. different embodiments of the invention can be made withoutdepartingfrorn the spirit and scope thereof, it is intended that allmatters shown in the accompanying, drawings and. described. hereinbefore:shall be interpreted. as. illustrative and not in alimiting sense.

Whatis claimed as new is:

1. A circuit interrupter for opening a high voltage circuit.isolatingdevice such as a disconnecting fuse, disconnectingswitch or the like,normally carrying line current and. havinga normally energized terminalcontact member and a current carryingmember movable into .;and out ofengagement therewith comprising, in combination, a. tubularinsulatinghousinghavinga conducting member secured thereto carryingexternallyextending contact means for electrical and mechanicalconnection to said contact member, an inner insulating sleeve relativelyslidably mounted withinsaid housing havingaconducting member securedthereto carryingexternally extending contact making means forelectricalconnection to said current carrying member; said .contactmaking means including a conductingarm extending along said tubularinsulating housing and movable longitudinallythereof together with'saidinner insulating sleeve and havingat. its outer end a longitudinallyextending socket with hearings on opposite sides thereof alongian axisperpendicular to the longitudinal axis of said socket, a spring plungerslidably' mounted in said socket having a spring urging the sameoutwardly, a 'strut' pivot shaft journale d in said bearings andprojecting at one end from said conducting arm on the side away fromsaid insulating housing and carrying cam means intermediate its ends forcooperating with saidfispring plunger to bias said strut pivot shaft toa central position, a strut rockably mounted intermediate its ends onsaid projecting end of said strut pivot shaft transversely of the axisof rotation thereof and biased toward said insulating housing, a prongextending laterally from said strut for electrical and mechanicalconnection to said current carrying member, and a keeper rockablymounted about two axes at right angles to each other on said strut andcooperating with said prong for engaging said current carrying member, apair of separable contacts in said sleeve connected respectively to saidconducting members, and means for separating said contacts to open thecircuit therethrough.

2. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve and having at its outer end a longitudinally extending socketwith hearings in opposite sides thereof along an axis perpendicular tothe longitudinal axis of said socket, a headed spring plunger slidablymounted in said socket having a coil compression spring therearoundurging the same outwardly, shoulder means in said socket cooperatingwith the head of said plunger to limit the inward movement thereof, astrut pivot shaft journaled in said bearings and projecting at one endfrom said conducting arm on the side away from said insulating housingand carrying cam means intermediate its ends for cooperating with saidhead of said spring plunger to bias said strut pivot shaft to a centralposition, a strut rockably mounted intermediate its ends on saidprojecting end of said strut pivot shaft trans versely of the axis ofrotation thereof and biased toward said insulating housing, 3. prongextending laterally from said strut for electrical and mechanicalconnection to said current carrying member, and a keeper rockablymounted about two axes at right angles to each other on said strut andcooperating with said prong for engaging said current carrying member, apair of separable contacts in said sleeve connected respectively to saidconducting members, and means for separating said contacts to open thecircuit therethrough.

3. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve, a strut rockably mounted about two axes at right angles to eachother intermediate its ends on the outer end of said conducting arm, aprong extending laterally from said strut for elec trical and mechanicalconnection to said current carrying member, said strut having alongitudinally extending recess spaced from said prong with bearings onopposite sides along an axis perpendicular to the longitudinal axis ofsaid recess, a keeper plunger slidably mounted in said recess, a springbiasing said keeper plunger outwardly of said recess,

keeper pivot shaft journaled in the last mentioned bearings andprojecting at one end from the side of said strut away from said tubularinsulating housing and having cam means intermediate its endscooperating with said keeper plunger to bias said keeper pivot shaft toa central position, and a keeper rockably mounted at one end on saidprojecting end of said keeper pivot shaft transversely of its axis ofrotation and biased away from said strut and cooperating with said prongfor engaging said current carrying member; a pair of separable contactsin said sleeve connected respectively to said conducting members, andmeans for separating said contacts to open the circuit therethrough.

4. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve, a strut rockably mounted about two axes at right angles to eachother intermediate its ends on the outer end of said conducting arm, aprong extending laterally from said strut for electrical and mechanicalconnection to said current carrying member, said strut having alongitudinally extending recess spaced from said prong with bearings onopposite sides along an axis perpendicular to the longitudinal axis ofsaid recess, a keeper plunger guide at the base of said recess, a headedkeeper plunger in said recess having a stem guided in said keeperplunger guide with its movement into said recess being limited thereby,a coil compression spring surrounding said keeper plunger and biasingthe same outwardly of said recess, a keeper pivot shaft journaled in thelast mentioned bearings and projecting at one end from the side of saidstrut away from said tubular insulating housing and having cam meansintermediate its ends cooperating with the head of said keeper plungerto bias said keeper pivot shaft to a central position, and a keeperrockably mounted at one end on said projecting end or" said keeper pivotshaft transversely of its axis of rotation and biased away from saidstrut and cooperating with said prong for engaging said current carryingmember; a pair of separable contacts in said sleeve connectedrespectively to said conducting members, and means for separating saidcontacts to open the circuit therethrough.

5. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means in- 13 cluding aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve and having at its outer end a longitudinally extending socketwith bearings on opposite sides thereof along an axis perpendiculartothe longitudinal axis of said socket, a spring plunger slidablymounted on said socket having a spring urging the same-outwardly,a strutpivot shaft journaled in said bearings and projecting at one end fromsaid conducting arm on the side away from said insulating housing andcarrying cam means intermediate its ends for cooperating with saidspring plunger to bias said strut pivot shaft to a central position, astrut rockably mounted intermediate its ends on said projecting end ofsaid strut pivot shaft transversely of the axis of rotation thereof andbiased toward said insulating housing, a prong extending laterally fromsaid strut for electrical and mechanical connection to said currentcarrying memher, said strut having a longitudinally extending recessspaced from said prong with bearings on opposite sides along an axisperpendicular to the longitudinal axis of said recess, a keeper plungerslidably mounted in said recess, a spring biasing said keeper plungeroutwardly of said recess, a keeper pivot shaft journaled in the lastmentioned bearings and projecting at one end from the side of said strutaway from said tubular insulating housing and having cam meansintermediate its ends cooperating with said keeper plunger to bias saidkeeper pivot shaft to a central position, and a keeper rockably mountedat one end on said projecting end of said keeper pivot shafttransversely of its axis of rotation and biased away from said strut andcooperating with said prong for en gaging said current carrying member;a pair of separable contacts in said sleeve connected respectivelyto'said conducting members, and means for separating said contacts toopen the circuit therethrough.

6. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable intoand out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve and having at its outer end a longitudinally extending socketwith bearings on opposite sides thereof along an axis perpendicular tothe longitudinal axis of said socket; a headed spring plunger slidablymounted in said socket having a coil compression spring therearoundurging the same outwardly, shoulder means in said socket cooperatingwith the head of said plunger to limit the inward movement thereof, astrut pivot shaft journaled in said bearings and projecting at one endfrom said conducting arm on the-side away from said insulatinghousing'and carrying cam means intermediate its ends for cooperatingwith said head of said spring plunger to bias said strut pivot'shaft toa central position, a strut rockably mounted intermediate its ends onsaid projecting end of said strut pivot shaft transversely of the axisof rotation thereof and biased toward said insulation housing, a prongextending laterally from said strut for electrical and mechanicalconnection to said current carrying mem ber,said strut having alongitudinally extending recess spaced from said prong with bearings onopposite sides along an axis perpendicular to the longitudinal axis ofsaid recess, a keeper plunger guide at the base of said 14 recess, aheaded keeper plunger in said recess having a stem' guided in saidkeeper plunger guide with its movement into said recess being limitedthereby, a coil compression spring surrounding said keeper plunger andbiasing the same outwardly of said recess, a keeper pivot shaftjournaled in the last mentioned bearings and projecting at one end fromtheside of said strut away from said tubular insulating housing andhaving cam means intermediate its ends cooperating with the head of saidkeeper plunger to bias said keeper pivot shaft to a central position,and a keeper rockably mounted at one end on said projecting end of saidkeeper pivot shaft transversely of its axis of rotation and biased awayfrom said strut and cooperating with said prong for engaging said'current carrying member; a pair of separable contacts in said sleeveconnected respectivelyto said conducting members, and means forseparating said contact to open the circuit therethrough.

7. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a

tubular insulating housing having a conducting member secured theretocarrying externally extending contact means for electrical andmechanical connection to said contact memeber, an inner insulatingsleeve relatively slidably mounted within said housing having aconducting member secured thereto carrying externally extending contactmaking means for electrical connection to said current carrying member;said contact making means including a conducting arm extending alongsaid tubular insulating housing and movable longitudinally thereoftogether with said inner insulating sleeve and having a universal jointat its outer end, a strut mounted intermediate its ends on saiduniversal joint, a prong extending laterally from said str ut fromelectrical and mechanical connection to said current carrying member,and a keeper rockably mounted about two axes at right angles to eachother on said strut and cooperating with said prong for engaging saidcurrent carrying member; a pair of separable contacts in said sleeveconnected respectively to said conducting members, meansfor separatingsaid contacts to open the circuit therethrough, and a latch ofinsulating material rockably mounted on said conducting arm between saiduniversal joint and said inner insulating sleeve and biased into thepath of said insulating housing to hold the same and said innerinsulating sleeve in separated position after said contacts haveseparated.

8. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member'secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve and having at its outer end a longitudinally extending socketwith bearin'gs on opposite sides thereof along an axis perpendicular tothe longitudinal axis of said socket, a spring plunger slidably mountedin said socket having a spring urging the same outwardly, a strut pivotshaft journaled in said bearings and projecting at one end from saidconducting min on the side away from said insulating housing andcarrying cam means intermediate its ends for cooperating with saidspring plunger to bias said strut pivot shaft to a central position, astrut rockably mounted intermediate its ends on said projecting end ofsaid strut pivot shaft transversely of the axis of rotation thereof andbiased toward said insulating housing, a prong extending laterally fromsaid strut for electrical and mechanical connection to said currentcarrying member, said strut having a longitudinally extending recessspaced from said prong with bearings on opposite sides along an axisperpendicular to the longitudinal axis of said recess, a keeper plungerslidably mounted in said recess, a spring biasing said keeper plungeroutwardly of said recess, a keeper pivot shaft journaled in the lastmentioned bearings and projecting at one end from the side of said strutaway from said tubular insulating housing and having cam meansintermediate its ends cooperating with said keeper plunger to bias saidkeeper pivot shaft to a central position, a keeper rockably mounted atone end on said projecting end of said keeper pivot shaft transverselyof its axis of rotation and biased away from said strut and cooperatingwith said prong for engaging said current carrying memher, and a contactfinger including a conducting sleeve carried by one end of a coil springthe intermediate portion of which is disposed around a shaft carried bysaid strut and the other end of which bears against said strut formoving said conducting sleeve in alignment with said prong formaintaining contact engagement with said current carrying member; a pairof separable contacts in said sleeve connected respectively to saidconducting members, and means for separating said contacts to open thecircuit therethrough.

9. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conductting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to saidcontact member, an inner insulating sleeve relatively slidably mountedwithin said housing having a conducting member secured thereto carryingexternally extending contact making means for electrical connection tosaid current carrying member; said contact making means including aconducting arm extending along said said tubular insulating housing andmovable longitudinally thereof together with said inner insulatingsleeve and having at its outer end a longitudinally extending socketwith hearings on opposite sides thereof along an axis perpendicular tothe longitudinal axis of said socket, a headed spring plunger slidablymounted in said socket having a coil compression spring therearoundurging the same outwardly, shoulder means in said socket cooperatingwith the head of said plunger to limit the inward movement thereof, astrut pivot shaft journaled in said bearings and projecting at one endfrom said conducting arm on the side away from said insulating housingand carrying a rectangular cam intermediate its ends for cooperatingwith said head of said spring plunger to bias said strut pivot shaft toa central position, a strut rockably mounted intermediate its ends onsaid projecting end of said strut pivot shaft transversely of the axisof rotation thereof and biased toward said insulating housing, a prongextending laterally from said strut for electrical and mechanicalconnection to said current carrying member, said strut having alongitudinally extending recess spaced from said prong with bearings onopposite sides along an axis perpendicular to the longitudinal axis ofsaid recess, a keeper plunger guide at the base of said recess, a headedkeeper plunger in said recess having a stem guided in said keeperplunger guide with its movement into said recess being limited thereby,a coil compression spring surrounding said keeper plunger and bias ingthe same outwardly of said recess, a keeper pivot shaft journaled in thelast mentioned bearings and projecting at one end from the side of saidstrut away from said tubular insulating housing and having a flat camsurface intermediate its ends cooperating with the head of said keeperplunger to bias said keeper pivot shaft to a central position, a keeperrockably mounted at one end on said projecting end of said keeper pivotshaft transversely of its axis of rotation and biased away from saidstrut and cooperating with said prong for engaging said current carryingmember, and a contact finger including a conducting sleeve carried byone end of a coil spring the intermediate portion of which is disposedaround a shaft carried by said strut and the other end of which bearsagainst said strut for moving said conducting sleeve in alignment withsaid prong for maintaining contact engagement with said current carryingmember; a pair of separable contacts in said sleeve connectedrespectively to said conducting members, means for separating saidcontacts to open the circuit therethrough, and a latch of insulatingmaterial rockably mounted on said conducting arm between said strutpivot shaft and said inner insulating sleeve and biased into the path ofsaid insulating housing to hold the same and said inner insulatingsleeve in separated position after said contacts have separated.

10. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing and having alengthwise extending elongated slot in its outer surface and a sleeveterminal secured to its outer end, a guide key of insulating materialsecured to said housing intermediate it ends and projecting into saidslot for guiding said sleeve, a conductor rod carried at its inner endby said terminal on said housing and extending therefrom into said innerinsulating sleeve, a movable first arcing contact in endwise spacedrelation to the outer end of said conductor rod, spring and cable meansinterconnecting said arcing contact and said conductor rc-d, a camterminal having a latch engaging shoulder carried by said outer end ofsaid rigid conductor, a tubular metallic sleeve secured at its outer endto said first arcing contact and slidably mounted in and extendingthrough said inner sleeve to the inner end thereof, a latch carried bysaid inner end of said inner sleeve and cooperating with the inner endof said metallic sleeve to effect conjoint movement of said sleeves andextension of said spring and cable means when said inner sleeve is movedoutwardly of said housing, said latch being released from said metallicsleeve on engagement with said latch engaging shoulder to permit saidfirst arcing contact and said metallic sleeve to be withdrawn throughsaid inner sleeve under the biasing action of said spring means, andcontact means carried by said sleeve terminal for contact engagementwith said first arcing contact and constituting a second arcing contact.

11. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend; an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing having ametallic inner sleeve end insert telescoped into its inner end, and asleeve terminal telescoped into its outer end, the interengagingsurfaces of the ends of said sleeve and said insert and said sleeveterminal being tapered and cemented together, a conductor rod carried atits inner end by said terminal on said housing and extending therefrominto said inner insulating sleeve, a movable first arcing contact inendwise spaced relation to the outer end of said conductor rod, springand cable means interconnecting said arcing contact and said conductorrod, a cam terminal having a latch engaging shoulder carried by saidouter end of said rigid conductor, a tubular mel7 tallic sleeve securedat its outer end to said first arcing contact and slidably mounted inand extending through said inner sleeve to the inner end thereof, alatch carried by said inner end of said inner sleeve and cooperatingwith the inner end of said metallic sleeve to effect conjoint movementof said sleeves and extension of said spring and cable means when saidinner sleeve is moved outwardly of said housing, said latch beingreleased from said metallic sleeve on engagement with said latchengaging shoulder to permit said first arcing contact and said metallicsleeve to be withdrawn through said inner sleeve under the biasingaction of said spring means, and contact means carried by said sleeveterminal for contact engagement with said first arcing contact andconstituting a second arcing contact.

12. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of saidhousing and having asleeve terminal secured to its outer end, a conductor rod carried at itsinner end by said terminal on said housing and extending therefrom intosaid inner insulating sleeve, a movable first arcing contact in endwisespaced relation to the outer end of said conductor rod, spring and cablemeans interconnecting said arcing contact and said conductor rod, a camterminal having a latch engaging shoulder and a stop shoulder carried bysaid outer end of said rigid conductor, a tubular metallic sleevesecured at its outer end to said first arcing contact and slidablymounted in and extending through said inner sleeve to the inner endthereof, a stop ring carried by the inner end of said metallic sleevefor engaging said stop shoulder to limit the extent of withdrawal ofsaid metallic sleeve from said rigid conductor and permit said innerinsulating sleeve and sleeve terminal thereon to continue their outwardmovement, a latch carried by said inner end of said inner sleeve andcooperating with the inner end of said metallic sleeve to effectconjoint movement of said sleeves and extension of said spring and cablemeans when said inner sleeve is moved outwardly of said housing, saidlatch being released from said metallic sleeve on engagement with saidlatch engaging shoulder to permit said first arcing contact and saidmetallic sleeve to be withdrawn through said inner sleeve under thebiasing action of said spring means, and contact means carried by saidsleeve terminal for contact engagement with said first arcing contactand constituting a second arcing terminal.

13. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend; an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing with alengthwise extending elongated slot in its outer surface and having ametallic inner sleeve end insert telescoped into its inner end, and asleeve terminal telescoped into its outer end; a guide key and stop ringof insulating material secured to said housing intermediate its endswith the key projecting into said slot for guiding said sleeve, theinterengaging surfaces of the ends of said sleeve and said insert andsaid sleeve terminal being tapered and cemented together, a conductorrod carried at its inner end by said terminal on said housing andextending therefrom into said inner insulating sleeve, a movable firstarcing contact in endwise spaced relation to the outer end of saidconductor rod, spring and cable means interconnecting said arcingcontact and said conductor rod, a cam terminal having a latch engagingshoulder and a stop shoulder carried by said outer end of said rigidconductor, a tubular metallic sleeve secured at its outer end to saidfirst arcing contact and slidably mounted in and extending through saidinner sleeve to the inner end thereof, a stop ring carried by the innerend of said metallic sleeve for engaging said stop shoulder to limit theextent of withdrawal of said metallic sleeve from said rigid conductorand permit said inner insulating sleeve and sleeve terminal thereon tocontinue their outward movement, a latch carried by said inner end ofsaid inner sleeve and cooperating with the inner end of said metallicsleeve to eifect conjoint movement of said sleeves and extension of saidspring and cable means when said inner sleeve is moved outwardly of saidhousing, said latch being released from said metallic sleeve onengagement with said latch engaging shoulder to permit said first arcingcontact and said metallic sleeve to be withdrawn through said liner andinner sleeve under the biasing action of said spring means, and contactmeans carried by said sleeve terminal for contact engagement with saidfirst arcing contact and constituting a second arcing terminal.

14. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing, having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing and having asleeve terminal secured to its outer end, a conductor rod' carried atits inner end by and rotatably mounted about its longitudinal axis onsaid terminal of said housing and extending therefrom into said innerinsulating sleeve, a movable first arcing contact in endwise spacedrelation to the outer end of said conductor rod, spring and cable meansinterconnecting said arcing contact and said conductor rod, said firstarcing contact and said spring and cable means being rotatablelongitudinally of said inner insulating sleeve together with saidconductor rod, a cam terminal having a latch engaging shoulder carriedby said outer end of said rigid conductor, a tubular metallic sleevesecured at its outer end to said first arcing contact and slidablymounted in and extending through said inner sleeve to the inner endthereof, a latch carried by said inner end of said inner sleeve andcooperating with the inner end of said metallic sleeve to effectconjoint movement of said sleeves and extension of said spring and cablemeans when said inner sleeve is moved outwardly of said housing, saidlatch be ing released from said metallic sleeve on engagement with saidlatch engaging shoulder to permit said first arcing contact and saidmetallic sleeve to be withdrawn through said inner sleeve under thebiasing action of said spring means, and contact means carried by saidsleeve terminal for contact engagement with said first arcing contactand constituting a second arcing contact, there being random relativepositioning of said arcing contacts resulting from the action of saidspring and the rotatable mounting of said conductor rod connected bysaid spring and cable means to said first arcing contact.

15. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing and having asleeve terminal secured to its outer end, a conductor rod carried at itsinner end by said terminal on said housing and extending therefrom intosaid inner insulating sleeve, a movable first arcing contact in endwisespaced relation to the outer end of said conductor rod, spring and cablemeans interconnecting said arcing contact and said conductor rod, a camterminal having a latch engaging shoulder carried by said outer end ofsaid rigid conductor, a tubular metallic sleeve secured at its outer endto said first arcing contact and slidably mounted in and extendingthrough said inner sleeve to the inner end thereof, a latch carried bysaid inner end of. said inner sleeve and cooperating with the inner endof said metallic sleeve to effect conjoint movement of said sleeves andextension of said spring and cable means when said inner sleeve is movedoutwardly of said housing, said latch being released from said metallicsleeve on engagement with said latch engaging shoulder to permit saidfirst arcing contact and said metallic sleeve to be withdrawn throughsaid inner sleeve under the biasin action of said spring means, and aplurality of contact fingers with longitudinal slots therebetweensecured to and disposed around the inner periphery of said sleeveterminal for contact engagement with said first arcing contact andconstituting a second arcing contact, said sleeve terminal having ventscoextensive and communicating radially with said slots to permit thedischarge of arc products therethrough to the atmosphere when saidsleeve terminal is moved out of said housing.

16. A circuit interrupter for opening a high volt-age circuitcomprising, in combination, a tubular insulating housing having aterminal at one end, an inner insulating sleeve relatively slidablymounted within and adapted to project out of the other end of saidhousing and having a sleeve terminal secured to its outer end, aconductor rod carried at its inner end by said terminal on said housingand extending therefrom'into said inner insulating sleeve, a movable'first arcing contact in endwise spaced relation to the outer end ofsaid conductor rod, spring and cable means interconnecting said arcingcontact and said conductor rod, a cam terminal having a latch engagingshoulder carried by said outer end of said rigid conductor, a liner ofarc extinguishing material within said inner sleeve near its outer end,a tubular metallic sleeve secured at its outer end to said first arcingcontact and slidably mounted in and extending through said liner to saidinner end of said inner sleeve, a latch carried by said inner end ofsaid inner sleeve and cooperating with the inner end of said metallicsleeve to effect conjoint movement of said sleeves and extension of saidspring and cable means when said inner sleeve is moved outwardly of saidhousing, said latch being released from said metallic sleeve onengagement with said latch engaging shoulder to permit said first arcingcontact and said metallic sleeve to be withdrawn through said liner andinner sleeve under the biasing action of said spring means, a pluralityof contact fingers carried by said sleeve terminal for contactengagement with said first arcing contact and constituting a secondarcing contact, and an arc shield carried by said inner sleeve andcoextensive with the outer end of said liner and the inner ends of saidcontact fingers for protecting the inner surface of said inner sleevefrom the heat of the are formed on separation of said arcing contacts.

17. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing and having asleeve terminal'secured to its outer cnd,,,a conductor rod carried atits inner end by and rotatably mounted about its longitudinal axis onsaid terminal of said housing and extending therefrom into said innerinsulating sleeve, a movable first arcing contact in endwise spacedrelation to the outer end of said conductor rod, spring and cable meansinterconnecting said arcing contact and said conductor rod, said firstarcing contact and .said spring and cable means being rotatablelongitudinally of said inner insulating sleeve together with saidconductor rod, a cam terminal having a latch engaging shoulder carriedby said outer end of said rigid conductor, a liner of arc extinguishingmaterial within said inner sleeve near its outer end, a tubular metallicsleeve secured at its outer end to said first arcing contact andslidably mounted in and extending through said liner to said inner endof said inner sleeve. a latch carried by-said inner end .of said innersleeve and cooperating with the inner end of said metallic sleeve toeifect conjoint movement ofsaid sleeves and eXtfinsion of said springand cable means when said inner sleeve is moved outwardly of saidhousing, said latch being released from said metallic sleeve onengagement with said latch engaging shoulder to permit said'first arcingcontact and said metallic sleeve to be withdrawn through said liner andinner sleeve under the biasing action of said spring 20 means, aplurality of contact fingers with lie 2"l slots therebetween secured toand disposed around the inner periphery of said sleeve terminal forcontact engagement with said first arcing contact and ccnstituti a 0ndarcing contact, there being random relative p dt ing of said arcingcontact resulting from the rotatable mounting of said conductor rodconnected by said spring and cable means to said first arcing contact,said terminal having vents coextensive and communicati. radially withsaid slots to permit the discharge of ar arc shield carried by saidinner sleeve and coe: with the outer end of said liner and the innerends of contact fingers for protecting the inner surface of s: innersleeve from the heat of the are formed on scparation of said arcingcontacts.

18. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular housing having a terminal at one end; an innerins sleeve relatively slidably mounted within and adapted to project outof the other end of said housing with a lengthwise extending elongatedslot in its outer surface and having a metallic inner sleeve end inserttelescoped into its inner end, and a sleeve terminal telescoped into itsouter end; a guide key of insulating material secured to said housingintermediate its ends and projecting into said slot for guiding saidsleeve, the interengaging surfaces of the ends of said sleeve and saidinsert and said sleeve termina being tapered and cemented together, aconductor rod carried at its inner end by and rotatably mounted aboutits longitudinal axis on said terminal on said housing and extendingtherefrom into said inner insulating sleeve, movable first arcingcontact in endwise spaced relation to the outer end of said conductorrod, spring and cable means interconnecting said arcing contact and saidcon ductor rod, said first arcing contact and said spring and cablemeans being rotatable longitudinally of said inner insulating sleevetogether with said conductor rod, a cam terminal having a latch engagingshoulder a d a stop shoulder carried by said outer end of said riconductor, a liner of arc extinguishing material within 2: d innersleeve near its outer end, a tubular metallic sleeve mounted in andextending through said liner to said inner end .of said metallic sleevefor engaging said stop shoulder to limit the extent of withdrawal ofsaid metaliic sleeve from said rigid conductor and thereby the extent ofv drawal of said inner sleeve from said housing, carried by said innerend of said inner sleeve and cooperating with the inner end of saidmetallic sleeve to client conjoint movement of said sleeves andextension of said spring and cable means when said inner sleeve is movedoutwardly of said housing, said latch being released from said metallicsleeve on engagement with said latch en ing shoulder to permit saidfirst arcing contact and d metallic sleeve to be withdrawn through saidliner and inner sleeve under the biasing action of said spring means, aplurality of contact fingers with longitudinal slot between secured toand disposed around the inner criphery of said sleeve terminal forcontact engagement with said first arcing contact and constituting asecond arcing contact, there being random relative positioning of saidarcing contacts resulting from the rotatable mounting of said conductorrod connected by said spring and cable means to said first arcingcontact, said sleeve terminal having vents coextensive and communicatingradially with said slots to permit the discharge of are productstherethrough to the atmosphere when said sleeve terminal is moved out ofsaid housing, and a metallic arc shield carried by said inner sleeve andcoextensive with the outer endof said liner and the inner ends of saidcontact fingers for protecting the inner surface of said inner sleevefrom the .heat of the are formed on separation of said arcing contacts.

19. A circuit interrupter for opening a high voltage circuit isolatingdevice such as a disconnecting fuse, disconnecting switch or the like,normally carrying line current and having a normally energized terminalcontact member and a current carrying member movable into and out ofengagement therewith comprising, in combination, a tubular insulatinghousing having a conducting member secured thereto carrying externallyextending contact making means for electrical connection to said contactmember, an inner insulating sleeve relatively slidably mounted Withinsaid housing having a conducting member secured thereto with anexternally extending conducting arm carrying contact making means forelectrical connection to said current carrying member, said armextending along said tubular insulating housing and movablelongitudinally thereof together with said inner insulating sleeve andhaving at its outer end a longitudinally extending socket with bearingson opposite sides thereof along an axis perpendicular to thelongitudinal axis of said socket, a spring plunger slidably mounted insaid socket having a spring urging the same outwardly, a strut pivotshaft journaled in said bearings and projecting at one end from saidconducting arm on the side away from said insulating housing andcarrying cam means intermediate its ends for cooperating with saidspring plunger to bias said strut pivot shaft to a central position, astrut rockably mounted intermediate its ends on said projecting end ofsaid strut pivot shaft transversely of the axis of rotation thereof andbiased toward said insulating housing, a prong extending laterally fromsaid strut for electrical and mechanical connection to said currentcarrying member, a pair of separable contacts in said sleeve connectedrespectively to said conducting members, spring means connected to oneof said contacts and acting to bias it for movement away from the othercontact with a force depending upon the extent of relative movementapart of said housing and sleeve, and means for releasing said onecontact for movement under the influence of said spring when said sleevehas been moved relatively away from said housing to a given position.

20. A circuit interrupter for opening a high voltage circuit comprising,in combination, a tubular insulating housing having a terminal at oneend, an inner insulating sleeve relatively slidably mounted within andadapted to project out of the other end of said housing and having asleeve terminal secured to its outer end, a conductor rod carried at itsinner end by and rotatably mounted about its longitudinal axis on saidterminal of said housing and extending therefrom into said innerinsulating sleeve, a movable first arcing contact in endwise spacedrelation to the outer end of said conductor rod, spring meansinterconnecting said arcing contact and said conductor rod, said'firstarcing contact and said spring means being rotatable longitudinally ofsaid inner insulating sleeve together with said conductor rod, latchmeans operatively interconnecting said movable first arcing contact andsaid inner sleeve to etfect conjoint movement thereof and extension ofsaid spring means when said inner sleeve is moved outwardly of saidhousing, means for releasing said latch means whereby said first arcingcontact is withdrawn through said inner sleeve under the biasing actionof said spring means, and contact means carried by said sleeve terminalfor contact engagement with said first arcing contact and constituting asecond arcing contact, there being random relative positioning of saidarcing contacts resulting from the action of said spring means and therotatable mounting of said conductor rod connected by said spring meansto said first arcing contact.

References Cited in the file of this patent UNITED STATES PATENTS

